328 : Economy of Fuel. 
be entirely freed from inconvenience on account of their occasional 
ction, it is only necessary to provide an escape in the manner 
indicated at F. The kitchen fire place is of course completely closed 
during the winter. By the adoption of this plan, every flue in the 
house except one, is rendered useless; and much worse than useless, 
because, besides occupying a great space, they carry off the hot air 
which is sent up from the furnace. And yet they do not perform all 
the purposes of ventilation, since their apertures are below the prop- 
er level for that object. - Seven out of eight have conenen ae 
closed at the top, by boards laid in mortar. 
Ventilation, when required, is readily effected by letting down 
sash from the top. 
From November to April, (the time this apparatus is in use) the 
average consumption of anthracite is one ton per month; and no 
- fuel whatever is required except a little charcoal, and a trifling 
quantity of light wood for rekindling the fire, should it ss 
become extinct. 
Canvass has been adopted to form the air shenlini because it is 
lighter, cheaper, more manageable than either iron or brick, and oc 
Cupies no space of importance, when removed for the summer. 
Where such removal is not desirable, or where the slightest danger 
is apprehended, it were probably better to form it of some ordinary 
building material. The whole of the above apparatus aeons - 
perhaps be improperly termed a tent furnace. 
_ As already stated, the gas pipe in the actual arrangement oe 
described, passes into a kitchen chimney, and the column C, is omit- 
ted; ——— considerable loss is sustained notwithstanding the 
quantity of pipe enclosed in the air chamber. 
In order to assure myself of the practicability of heating an apart 
ment on the third floor, by means of the gas thus escaping: from the 
kitchen, as well as to determine the relation of the temperature of 
the escaping gas, to that of the open air, and to the highest tempera 
ture required in the rooms below, experiments were made at the top 
of the chimney, and at several stages below. Care was taken t 
allow the thermometer, (which for this purpose was suspended to @ 
measuring line; ) time to attain the temperature of the gas at each 
stage, and then to withdraw it quickly, when about to be examined. 
Exp. 1. To this experiment the air was at 40°; the parlor D, 
72°; the gas at the very top of the rE 2 134°; _— at sos? - 
below, 139°. 
